Sergi Roberto

Aleix Vidal has turned out to be the bust of all busts and with Dani Alves walking out on the club in June, Sergi Roberto has suddenly become the first-choice right-back at Barcelona... which is impressive for a central midfielder.

Be under no illusions, reinforcements for the role will arrive in January but there's nobody else who can play here for the moment.

If he can't get to 100% fitness, Javier Mascherano may have to fill in.

Gerard Pique

Hot head: Gerard Pique will be at the centre of attention (Photo: AFP/Getty)

, who took the opportunity as he and his side celebrated a treble in 2015.

He loves the big games and he loves winning them, which is just as well as Barcelona have done a lot of that in recent years.

The likelihood is that he'll be celebrating again on Saturday. If not, he'll be the player fronting up to the press.

Javier Mascherano

Critical Masche: The Argentine will perform a vital role in the centre of defence (Photo: David Ramos)

The Argentine is under pressure from new signing Samuel Umtiti to start in central defence but you'd expect experience to win out for a game of this magnitude.

The outside chance is that he may have to fill in at right-back due to injuries, which would severely weaken Barca's backline.

Recent experiments with a back three haven't worked out so well.

Jordi Alba

Jord dropping: Alba will be a key player (Photo: Reuters)

Alba has to tread the tightrope between flying up that left flank unopposed and tracking whoever Zidane opts to play on that side.

And Dani Carvajal's overlapping runs from right-back are what Alba will need to keep an eye on.

But first and foremost he needs to return to full fitness otherwise Luis Enrique may go with Lucas Digne instead.

Sergio Busquets

Power Serg: Busquets is in top form (Photo: Getty)

The rangy strides of Busquets patrolling the centre of the park have been a rare constant in a season full of injuries for Barcelona.

And the 28-year-old is still a key cog in this machine.

Luis Enrique last season described him as the “best midfielder in the world” - - and this is his stage to prove it.

Andres Iniesta

Bouncing back: Iniesta has recovered from injury to lead Barcelona (Photo: Getty)

The Barcelona skipper has struggled with injury but those around the Nou Camp club are backing him to play.

Even if he doesn't start, you'd hope he could make a cameo from the bench.

Iniesta is, regardless, a player to savour while he is still around.

Ivan Rakitic

Spice Rak: The Croat has had a great season (Photo: REUTERS/Heino Kalis)

The unsung hero in Barcelona's lineup, Ivan Rakitic has shown how you replace Xavi...

...by not trying to replace Xavi.

Bought cheaply from Sevilla, Rakitic has made Barca more direct and sped up their transitions to change this side from one centred around possession to a lightning-quick attacking unit.

Lionel Messi

Can't catch him: Messi receiving special attention (Photo: Reuters)

Messi is the brightest star in football's greatest-ever forward line. Stop him if you can.

With Barcelona struggling for form, a decisive intervention from the Argentinean superstar would be much appreciated by the club's top brass and would do no harm in his upcoming contract negotiations.